If you’re watching your weight, you might want to include some extra olive oil in your diet to help you feel full longer. Researchers in Germany and Austria tested four edible fats: lard, butterfat, rapeseed oil and olive oil to assess their ability to satiate appetite. Over three months, the investigators gave study participants daily 500-gram portions of low-fat yogurt enriched with one of the four fats. Otherwise, the participants continued with their normal diets. Of the four fats, olive oil proved the most satiating based on participant reports, and blood tests showing that regular consumption of olive oil led to higher blood levels of serotonin, a hormone associated with satiety. Because rapeseed oil and olive oil contain similar fatty acids, the team next tested aroma extracts from olive oil to see if they had any bearing on satiety. They provided one group of participants with a daily serving of yogurt containing added olive oil aroma extracts and the other group with plain yogurt, and found that daily calorie intake among participants in the olive oil group remained the same while control group participants consumed 176 more calories a day and had lower blood levels of serotonin. During the study, no participant in the olive oil group gained weight. The researchers concluded that olive oil aroma is capable of helping regulate satiety.